S-C3N6 monolayer by atomic doping serving as solar cells and photocatalyst

Abstract

Atomic doping is an effective method to adjust the electronic and optical properties of s-C3N6. Herein, we studied the effects of atomic doping (S, Cl, Na and Mg) on the electronic, optical and redox properties of s-C3N6 monolayer by first-principles calculations. We consider the substitutional doping of non-equivalent C or N atoms and interstitial doping at the hole position. The results show that atomic doping can effectively adjust the band gap of s-C3N6 (2.59 eV) monolayer. Most notably, we found that S(Nl)-s-C3N6 is a quasi-direct band gap semiconductor with a band gap of 1.27 eV and the theoretical photovoltaic efficiency of S(Nl)-s-C3N6 is 31.84%, which indicates it has the potential to be used in thin-film solar cells. In addition, Cl6@s-C3N6 meets the conditions of photocatalytic water splitting at pH = 7, and the Mg6@s-C3N6 monolayer appears the reduction ability. Meanwhile, the atomic doped s-C3N6 monolayer enhances the absorption intensity in the visible light range. The emergence of redox capacity and the enhancement of the absorption coefficient in carbon nitride monolayer via atomic doping reveals an exciting material platform for designing novel photovoltaic cells and nanoelectronics devices.